Chemistry Exam Past Questions and Answers | JAMB, WAEC and NECO

Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.

• Question 921:

  Which of the following methods is commonly used to remove suspended impurities from water?

  Options:
  A) Fluoridation
  B) Chlorination
  C) Filtration
  D) Distillation
  Show Answer
  The correct answer is C .
• Question 922: A compound gives an orange-red colour to non-luminous flame. This compound is likely to contain Options:
  A) Na⁺
  B) Ca²⁺
  C) Fe³⁺
  D) Fe²⁺
  Show Answer
  The correct answer is B .
• Question 923: Which of the following statements is true about 2-methylpropane and butane Options:
  A) They have different number of carbon atoms
  B) They are members of same homologous series
  C) They have the same boiling points
  D) They have the same chemical properties
  Show Answer
  The correct answer is D .
• Question 924:

  What are the possible oxidation numbers of an element if its atomic number is 17?

  Options:
  A) -1 and 7
  B) -1 and 6
  C) -3 and 5
  D) -2 and 6
  Show Answer
  The correct answer is A .
• Question 925:

  The Consecutive members of an alkane homologous series differ by

  Options:
  A) CH
  B) CH${}_2$
  C) CH${}_3$
  D) C${}_n$H${}_n$
  Show Answer
  The correct answer is B .
• Question 926:

  56.00cm³ of a gas at S.T.P. weighed 0.11g. What is the vapour density of the gas?
  [Molar volume of a gas at S.T.P = 22.4dm³]

  Options:
  A) 11.00
  B) 22.00
  C) 33.00
  D) 44.00
  Show Answer
  The correct answer is B .
• Question 927: A solid X when heated gives off a brown gas. If X is soluble in excess sodium hydroxide solution but insoluble in excess ammonium hydroxide solution, then X is Options:
  A) basic lead carbonate
  B) lead (II) nitrate
  C) sodium carbonate
  D) zinc nitrate
  E) sodium nitrate
  Show Answer
  The correct answer is B .
• Question 928: Sodium hydrogen should be stored in properly closed containers because it? Options:
  A) readily asborbs water vapour to air
  B) is easily oxidize by atmospheric oxygen
  C) turns golden yellow when exposed to light
  D) melts at a low temperature
  Show Answer
  The correct answer is A .
• Question 929:

  

  The lUPAC name for

  Options:
  A) 1-methyl pentane
  B) 3-methylbutane
  C) 2-methylbutane
  D) 1-dimethyl propane
  Show Answer
  The correct answer is C .
• Question 930:

  SO${}_2$ + O${}_2$ 2SO${}_3$

  In the reaction above, the most suitable catalyst is?

  Options:
  A) chromium(vi)oxide
  B) iron(iii)oxide
  C) copper(i)oxide
  D) vanadium(v)oxide
  Show Answer
  The correct answer is D .